Plasticizer Bisphenol A interferes with enamel formation

Plasticizer Bisphenol A prevents enamel formation

06/13/2013

The plasticizer bisphenol A impedes the formation of enamel, a French researcher from the Universite Paris-Descartes found. According to the results of the investigation, there is a connection between the chemical bisphenol A and the mineralization disorder Molar-Incisor-Hyponmineralisation. Scientists are making the plasticizer responsible for a number of other health problems, including overweight and infertility. Diabetes, cancer and cardiovascular problems are also linked to the estrogen-like substance.

Animal experiments led French scientists to the realization
The im „American Journal of Pathology“ published study led by Katia Einemon examined the effects of bisphenol A on the development of enamel in rats. The study was based on a suspected association between the increasing burden of hormone-like chemicals and more and more cases of molar incisor hyponmineralization. This mineralization disorder leads to yellowish-white or brown spots during enamel formation, especially in the anterior incisors and posterior molars. „Affected teeth are usually sensitive to thermal stimuli. Sometimes the daily dental care of these teeth is very painful“, writes the University Hospital Giessen.

The animal experiments of the French scientists were limited to the first 30 or 100 days after the birth of the rats. The concentration of bisphenol A used was well below the European Union limit of 50 micrograms per kilogram of body weight. After 30 days, however, 75 percent of rat teeth showed the expected changes: white spots and brittle edges. Interestingly, however, scientists' findings can only be reconstructed within the first 30 days after birth. The assumption is obvious that the changes „only intervene in a specific time window of the development phase“ - a finding consistent with observations of human mineralization disorder.

When enamel forms, the body works in two phases: First, a protein scaffold is built on which minerals deposit. Subsequently, the proteins are broken down and the solid enamel is formed by crystallization. How bisphenol A interferes with the development process revealed further test phases of the advancement team in this context. Apparently, the plasticizer causes an excess of proteins during the first phase and hinders the degradation system during the second phase. The proteins are not sufficiently removed, interfere with the crystallization and lead to soft, brittle tooth enamel - the crucial symptom of Molar incisor hyponmineralization.

Further research should clarify open questions
To what extent bisphenol A hinders enamel formation in detail should now be investigated. A final proof for the connection between bisphenol A and the mineralization disorder will follow, explains the research team. However, they assume that the animal processes can be transferred to the human body.

Bisphenol A: Consumers are in danger every day
The biggest problem with this finding is that bisphenol A is used to make plastics and is contained in countless everyday objects - despite warnings from scientists and environmental organizations. In some countries, the use of the plasticizer in children's products was banned, in this country, at least the use in baby bottles is prohibited. The EU food authority responsible for such bans was previously under the influence of lobbyists, researched the Mitteldeutscher Rundfunk 2011. The decisions were made on the basis of falsified study results.

Only about two weeks ago, US scientists determined that bisphenol A has a lasting negative impact on human brain development. By testing with pregnant mice, the researchers came to the conclusion that even small doses of the plasticizer has a significant effect on the brain development of the offspring. Both male and female mice showed therefore clear behavioral problems. Males were clearly more research-minded and daring, females much more anxious than usual. The scientists attribute this effect partly to effects of the plasticizer on estrogen receptors in different brain areas. (Lb)

Image: Thommy Weiss